Self-heating can



' Nov. 24, 1959 A. DEL RASO SELF-HEATING CAN Filed April 1, 1958 2 Sheets-Sheet 1 E /3 I /z I I 3 1 fif v 7 1 L T79 l Q m /5 Q NVENTOR. 4MEe/ca .0 54 2450, 30 3 27 BY %%W I l ATTOE/VEYS Nov. 24, 1959 A. DEL RASO 2,914,061

SELF-HEATING CAN Filed April 1, 1958 2 Sheets-Sheet 2 IN VENTOR. flMI/C'O 0E4 2480,

nr-rae/ws' vs Unimd States Patent This invention relates to containers, and more particularly to a can provided with impact-responsive self-heating means. I Y

A main object of the invention is to provide a novel and improved self-heating can which is simple in construction, which is relatively compact insize, and'which provides a means for quickly and effectively warming the contents thereof when desired.

A further object of the invention is to provide an improved can having impact-responsive self-heating means carried thereby, the self-heating means being normally secured to the can in an inconspicuous and protected manner but being available for use whenever it is'desired to heat the contents of the can, the can being inexpensively to fabricate, being arranged so that'a number of cans may be readily stacked vertically one on top of the other, and being safe touse. I

Other objects and advantages of the invention will become apparent from the following description and claim, and from the accompanying drawings, wherein:

Figure l is a top view, partly broken away, of an improved self heating can constructed inraccordance with the present invention. 3 i i Figure 2 is avertic line 2-2 of Figure l.

Figure 3 is a vertical cross-sectional view taken on the line 3-3' of Figure 2.

Figure 4 is an enlarged cross-sectional view taken on theline4-4 ofFigure 3. I

Figure 5 is an enlarged cross-sectional view taken substantially on the line 5-5 of Figure 3".-

a1 cross-sectional the ate portion of its cylindrical wall with an inwardly projecting, generally hemispherical detent lug 19 which is lockingly engageable with a heating cartridge holder 20 normally contained in the chamber 16, as will be present'ly' described.

The cylindrical main wall 12 of the food can 11 is formed of the usual relatively thin sheet metal material, the cartridge chamber 16 being formed of similar material, so that the cylindrical main wall is somewhat resilient and is readily yieldable.

The heating cartridge holder 20 comprises a main body 21 of heat-resistant material, such as asbestos composition, compressed to provide a generally rigid cylindrical member which is dimensioned so as to slidably engage in the cylindrical cartridge chamber 16. The body 21 is formed at its top end, as viewed in Figure 3, with a generally cylindrical cup-like recess 22 in which is mounted a firing cartridge 23 comprising combustible material of well known composition, the cartridge 23 comprising a non-combustible metallic container, in which the combustible heating chemicals are normally carried. The top Wall of the container, shown at 24, has centrally secured therein an ignition cap 25, also of Well knowncomposition, which is in ignitable relation to-the combustible material in the container 24 and i which is adapted to rapidly oxidize responsive to intense with an axial bore 26 extending from the bottom of the recess 22 to the bottom end of the body 21, providing an escape vent for steam or other products of combustion generated when the cartridge 23 is burning. The

Figure 6 is a bottom view of the structure shown in 5T1 Figure 5. H a

Figure 7 is an enlarged cross-sectional -detail'*view taken substantially on the line 7-7 of Figure 2.

Figure 8 is a cross-sectional detail view, similar to Figure 7, but showing the manner in which the side wall of the heating cartridge chamber resiliently deforms when the cartridge is rotated to its normal position in the cartridge chamber. a

Figure 9 is an enlarged cross-sectional detail view taken substantially on the line 9-9 of Figure 6.

Figure 10 is an enlarged vertical cross-sectional view showing the structure of Figure 3 but illustrating the heating cartridge in the process of being ignited.

Referring to the drawings, 11 generally designates a food can according to the present invention. Food can 11 comprises a cylindrical main wall 12, a flat top wall 13 provided with an upstanding rim 14 of substantial height, and an annular generally conical, downwardly flaring rigid bottom wall 15 formed centrally with the upstanding, generally cylindrical axial cartridge chamber 16.

As shown in Figure 3, the cartridge chamber 16 is formed with a generally conical rigid top wall 17 which is downwardly convergent and which is formed at its tip with a depending firing pin element 18. m

The cartridge chamber 16 is formed at the intermediouter' wall surface of, body 21 is formed with vertical grooves 27, extending for the full length of the body, also serving as an escape channel for steam or other gases developed by the heat of combustion of the burning cartridge 23.

; The outer wall surface of body 21 is formed adjacent the intermediate portion ofthe vertical groove 27 with a pair of oval recesses 28, 28 communicating with the vertical groove 27 by means of short horizontal groove portions 29, 29 of lesser depth than the groove 27 and the recesses 28, 28, as is clearly shown in Figure 9. The recesses 28, 28 are located at a position on. the body 21. such that the detent lug 19, when engaged in one of the recesses 28, 28, will support the cartridge in a position such as that shown in Figures 3 and 5, namely, with the ignition cap 25 located a short distance below the firing pin 18 and with the bottom end of the cartridge holder 20 projecting a short distance below the bottom plane of the can 11, said distance being slightly less than the height of the rim 14 on the top portion of the can. This enables the cans to be vertically stacked, one on top of the other, without exerting force on the cartridge holder 20, since the dependingportion of the cartridge holder 20 of an upper can is received in the recess defined by the rim 14 of a subjacent can.

In inserting a cartridge holder 20 into the chamber 16 of a can, the lug 19 is first aligned with the groove 27 in the side of the cartridge body 21, and the body is slid into the chamber 16 until-the lug 19 is substantially aligned with the short horizontal groove portions 29, 29. The lower end of the cartridge holder body 21 is then rotated so that the lug 19 rides into one of the short, shallow channels 29, causing the Wall of the chamber 16 to be flexed outwardly relative to the cartridge holder in the manner illustrated in Figure 8. Continued rotation of the cartridge holder causes the lug 19 to ,en-

ter the adjacent oval recess 28, and shown in Figure 9,

thus locking the cartridge holder in its normal position, shown in Figures 1 to 5.

The lower end of the cartridge holder body 21 is formed with thegripping'recess'es or knurls 30, asshown in Figures 2, and 10, to facilitate the manual rotation of the cartridge holder when inserting the cartridge holder into the cartridge chamber 16, as above described.

When it is desired to heat the contents of a can, the can is placed on a fiat surface and a rapid downward force is exerted thereon, causing the cartridge holder body 21 to be rapidly pushed upwardly in the cartridge chamber 16, whereby the firing pin 18 rapidly engages the ignition cap 25 with substantial impact, causing the cap to ignite, thereby igniting the heating chemicals in the cartridge element 23.

As previously explained, the oval recesses 28 engage the detent lugs 19 with sufficient force to normally retain the cartridge holder in its position shown in Figures 1 to 5, but the chamber wall is suificiently yieldable to allow the cartridge holder to be pushed upwardly into the chamber with sufiicient force and with sufficient rapidity to cause the firing pin 18 to ignite the cap 25 in the manner above described.

When the cartridge 23 ignites, an intense heat is generated in the upper portion of the cartridge chamber 16, causing the contents of the can 11 to be heated.

Should there be moisture or dust in the chamber 16, steam, or other products of combustion produced in the chamber because of the intense heat, escapes from the chamber through groove 27 and axial bore 26.

The metal shell 16 is impervious to smoke and flame but is an excellent conductor of heat, whereby the heat flows inwardly to the contents of the can at a relatively rapid rate but in a substantially uniform manner, since the chamber 16 is located substantially centrally with respect to the contents of the can.

The wall of the recess 22 containing the cartridge element 23 is of sufficient thickness to retard the transmission of heat through the wall chamber 16 enough to prevent scorching of the food material closely adjacent to the cartridge chamber 16.

The top and sides of the can 11 may be covered with a suitable insulating material to protect the user against burns from the hot metallic surfaces of the can when the can is being heated and to retain heat in the can. Thus, the main wall 12 of the can maybe provided with a paper wrapper 60 and the top of the can may be. provided with a paper cover disc 61. The members 60 and 61 may be utilized to carry any desired printed advertising or other information relating to the use of the can and its contents.

When the can is' in storage or on display prior to being used, the heating cartridge 23 can be conveniently and safely stowed in an invertedposition in its recess 22, whereby the cartridge cannot he accidentally fired.

The cartridge holder 20 is easily removable from the chamber 16 for the purpose of ejecting spent cartridges, and also to facilitate insertion of extra cartridges if desired. Thus, in cold weather extra cartridges may be used to bring the contents of the can to a desired temperature.

The heating cartridge 23 is preferably of a type which comprises an ignitible composition which liberates heat but no. gas,. such Vas-is disclosed in US. Patent No. 2,500,790 to O. G. Bennett.

While a specific embodiment of an improved self-heating food can has been disclosed in the forego'ng description, it will be understood that various modifications may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claim.

What is claimed is: v

In a food can, a vertical main Wall, a top wall secured to the top rim of said main wall, a bottom wall secured to the bottom rim of said main wall, said bottom wall being formed-with achamber rising a substantial distance vertically from the plane of. the bottom rim of said main wall, a depending firing pin element in the top portion of said chamber, a heating cartridge slidably mounted in saidchamber and projecting downwardly from said bottom wall, an inwardly projecting lug on the wall of said chamber, said cartridge being formed with a vertical groove at a side portion thereof slidably receivingsaid lug and with a laterally directed recess at the intermediate portion of said vertical groove in which the lug is receivable to lock the cartridge in the chamber, the wall of the chamber adjacent said lug being yieldable at times to allow the cartridge to be forced upwardly in the chamber, an impact-responsive ignition cap on said cartridge subjacent said firing pin element, and a container filled with combustible material and supported within the cartridge with said material in ignitable relation to said cap.

References Cit'edin the file of this patent UNITED STATES PATENTS 2,020,292 7 Eggert et al. Nov. 12,1935 FOREIGN PATENTS 158,259 Austria Mar. 26, 1940 498,552 France Apr. 22, 1919 

